Caller ID has become a popular telephone service feature. Caller ID is a telephone on-hook capability that provides a called party with information about the caller before the incoming call is answered. Conventionally, such information includes the date and time of the call and the caller's telephone number. A data message, preceded by a channel seizure signal, is sent in conjunction with the ringing signal from the central office to the called party during the silent interval after the first 20-Hz, 2-second ringing phase. The service offers several advantages to the called party subscriber. Identification of the calling party, as provided by the caller ID service, allows the called party to screen an incoming call personally before its completion and thereby to decide whether or not it is desirable to answer the call. Nuisance calls, such as advertising and solicitation calls, can be avoided if the identity of the caller is determined beforehand. Knowledge of caller identity also serves as a resource for dealing with and curtailing harassment calls.
Despite its many favorable aspects of which the above noted advantages are but a few, caller ID has raised objections with respect to callers' rights of privacy. Such rights have conventionally been honored by "nonpublished" and "non-listed" options. A non-listed telephone number is not printed in a telephone directory but available through operator assistance. A nonpublished telephone number is neither printed in a directory nor available through an operator. If the caller number identity is made known to a called party caller ID subscriber each time a call is made, the privacy afforded to a caller having an on-listed or nonpublished number is significantly compromised. Further, any caller may find it desirable to place a particular call without revealing origination identity to the called party. In such case, the caller must take the risk that the called party line does not subscribe to the caller ID service.
To accommodate caller privacy, a caller ID block service has been developed, whereby the identity of the call originating line, which subscribes to caller ID block, will not be transmitted to the called party. Although variations exist in the precise manner in which caller ID information selectively may be withheld, ultimately the caller ID data message simply is not transmitted to the called party station. With caller ID blocked, a call is directed to the called party for completion in the standard manner and the caller ID functionality, to which the called party has subscribed, is lost.
Commonly assigned U.S. Pat. No. 5,497,414, issued to Bartholomew on Mar. 5, 1996 and to which reference is hereby made, offers several approaches in balancing the competing objectives of the calling party who wishes privacy and the called party who seeks to know the origination of incoming calls. These approaches make use of the Advanced Intelligent Network (AIN) of the Public Switched Telephone Network (PSTN), whereby call processing is enhanced by a decision making capability. Predefined criteria can be applied to calls by screening incoming caller identities to determine, for example, whether specific calls are to be completed to the called parties, with or without caller ID information, or to be forwarded to other destinations. With such control, both the called party caller ID subscriber and the calling party caller ID block subscriber are given flexibility. The calling party ID block subscriber may define in advance the destinations to which calling identification need not be blocked. The called party caller ID subscriber, likewise, may define the origination locations from which calls having blocked caller ID may be routed to the called party destination.
The provision of privacy is a more complex undertaking in the voice mail environment, wherein messages are communicated among voice mailboxes that require address identification. A voice mail system (VMS) is a specialized computer system that digitizes, compresses and stores audio and other messages in digital form on one or more disk drives. Voice mail identification is normally associated with the telephone number of the voice mail subscriber. As the ability to send return messages is a normal and expected attribute of voice mail communication, data message protocol provides for message headings to include both sending and receiving addresses. Thus, in conventional systems the receiving voice mailbox gains access to the source identity information. Nevertheless, there is a public need for privacy in certain circumstances. For one example, a response to an initial message sent by a "battered spouse" may be desired without the answering spouse being able to obtain the originating identification that can readily be linked to information sought to be kept private. Of course, there are many less dramatic and varied instances requiring privacy.
Audio Message Interchange Specification (AMIS) standards are being developed to form a common language that network voice mail systems of different manufacture can support to communicate in an effective manner. An objective is to support the exchange of electronic messages in any media among public messaging services and premises-based messaging systems. Accommodation thus would be made for premises-to-premises messaging, messaging between public mail services and private mail systems, and the exchange of messages between individual public mail services which otherwise operate in stand alone mode. Public message transfer service is defined in CCITT Recommendation F.410.
A simple form of networking voice mail is the use of guest mailboxes, in which boxes can be assigned to persons outside the system. Voice mail networking can also encompass terminating voice mail on one switch to which other switches are connected with networking software. Another alternative would be to network the voice mail systems themselves.
Commonly assigned U.S. Pat. No. 5,680,442, issued to Bartholomew et al. on Oct. 21, 1997 and incorporated by reference herein, contains a detailed description of a system that effects transfer of voice mail messages among centralized messaging systems, utilizing existing equipment and network facilities that are connected to subscriber terminals. To avoid voice connection to, and ringing at, a recipient's telephone station when only delivery of a message to the mailbox is to occur, the voice trunking network and ringing of the telephone station corresponding to the recipient mailbox are blocked. An additional benefit is a significant lightening of the traffic load on the network trunking system.
A remaining disadvantage of existing systems is that message source addresses are delivered to the recipient voice mail system. The sender of the voice mail message is subject to risk that the recipient will have access to the source address and thus the sender's telephone number. With such information, the recipient would be able to call the sender even if that telephone number were private. Further information, such as the sender's residence address, also would be subject to discovery. The need thus exists for the ability to transfer voice mail messages without relaying address identification of a source mailbox.
In furtherance of this objective, a need exists for providing the recipient of an "anonymous" message with the ability to send a return message even though the identifying information of the originating message had been withheld. For example, the sender of the original message may simply want to receive a response to the message without engaging in an interactive conversation. Such a requirement may be desirable, for example, to avoid a harassing telephone call while still obtaining requested information in a response message. As another example, service or product information may be requested from a vendor in an initial anonymous message. Such information can be obtained in the response message without the requesting party being subjected to a live interactive telephone call with an annoying, time consuming sales pitch.